The crosswalks Captcha provides the most difficult cultural discrepancy for me. Some US crosswalks look like European "forbidden for all traffic" road markings. Pretty much the opposite of a crosswalk. I always have to do a double take on those.
And in India, they are commonly refereed to as "Zebra Crossing". No one refers to them as cross-walks and most have no idea about that term.
I failed a few recaptchas like that too, tho not due to language barrier, but because I didn't pick some things that didn't look like crossings at all. I am convinced that some of those supposed markings were not crossings at all but things that somehow got into google's labeling db as outright false positives.